1. The problem asks for the measure of angle 1 (m \angle 1) in a triangle where two other angles are given as 80° and 59°. 2. Recall the Triangle Angle Sum Theorem: The sum of the interior angles of a triangle is always 180°. 3. Using the theorem, we can write the equation: $$m \angle 1 + 80 + 59 = 180$$ 4. Simplify the sum of the known angles: $$80 + 59 = 139$$ 5. Substitute back into the equation: $$m \angle 1 + 139 = 180$$ 6. Solve for $m \angle 1$ by subtracting 139 from both sides: $$m \angle 1 = 180 - 139 = 41$$ 7. Therefore, the measure of angle 1 is 41°. Final answer: $m \angle 1 = 41^\circ$